Transmission compatibly

[Pindoctor]

Hi all, I have a 98 Tahoe 5.7 4x4 M30 Transmission. Does my tahoe have a 4l60e or 80e? Also what transmissions are compatible with it? The transmission will shift in all gears when cold and after 2 minutes of warming up it stops shifting and won't move. I found a 97 Silverado v8 4x4 tranny 4l60e and junk yards said it will not work with my tahoe and tranny pros said it might and dealers say it might, who's right?

Thanks.

 

[grimm]

Your truck was equipped with a 4L60E. The M30 is an RPO code designating this. A 4L80E would work, but you'd have to cut the crossmember on the frame, move it back, and reweld it to install properly. I think there's a couple added steps that I can't think of right now, someone else can verify I'm sure. A 4L65E should also work with less hassle. The 4L60E out of the Silverado should work, especially since its a 4x4 and its around the same model year. Should just be a direct fit. If you want to be 100 percent sure, get under your truck and underneath the Silverado to compare.

 

[T-Bagg]

I'm going to guess the junk yard is wrong/lying. The 1500 Suburbans and Tahoes share the same drive train. Just different length drive shafts. I'd bet a dollar you can swap the transmissions.

 

[Pindoctor]

I'm going to guess the junk yard is wrong/lying. The 1500 Suburbans and Tahoes share the same drive train. Just different length drive shafts. I'd bet a dollar you can swap the transmissions.

Okay but what about the bell housing, some told me that my tahoe has a bell housing that's comes apart or split, is that right, the silverado has a full bell housing that is together not split. And someone else told me that the 97 silverado tranny wold mess up my computer. The junk yards say 97 silverado are only specific to that year and they said 98 and 99 would work.

 

[crmzendrgone]

This might help.

http://www.truckforum.org/forums/ch...4l65-e-transmission-diagram-2.html#post133945

 

[T-Bagg]

This might be a dumb question. But is it serviced all the way with tranny fluid. My was shifting off a few days ago. Turns out I was about three quarts low.

Another option is to rebuild it your self. Monster Transmission sells parts kits to make the 4L60E stout as hell.

It's on my to do list.

 

[grimm]

Agree with T-Bagg. Maybe you don't need to replace it. Check your fluid levels. If you're just low... add some fluid and your probably good to go. If transmission fluid is black/burned, then you should start thinking about a rebuild or a replacement.

 

[Danny_Z56]

Hi all, I have a 98 Tahoe 5.7 4x4 M30 Transmission. Does my tahoe have a 4l60e or 80e? Also what transmissions are compatible with it? The transmission will shift in all gears when cold and after 2 minutes of warming up it stops shifting and won't move. I found a 97 Silverado v8 4x4 tranny 4l60e and junk yards said it will not work with my tahoe and tranny pros said it might and dealers say it might, who's right?

Thanks.

I had a 1994 B4U LT1 Chevy Caprice LS that did this too.

What my problem turned out to be was a bad PCM.My PCM was not telling the tranny to shift.It would shift while cold but once warmed up the tranny would not shift unless i did it manually.....1.2.3.D.

I got a used PCM for $82 from a local junk yard and installed it right there.When i left the bone yard my tranny shifted just fine,all the way home and the rest of the time i had the car.

This was my case and may not be yours.

 

[Pindoctor]

Well i took the Tahoe into the shop and i had them fix it. They said that the converter blew and it took out the pump, so thats why it wasnt moving after 2 mins of warming up. so after 1157.00 US its fixed. Thanks guys for your help.